code: def __init__(self, halo_ex):
      self.halo_ex = halo_ex
      self.stream1 = torch.cuda.Stream()
      self.stream2 = torch.cuda.Stream()
  
imports: import torch
  import torch.distributed
  from torch import nn
  import nccl_p2p_cuda
  import peer_memory_cuda
label_desc: Use image node_id 1 to create a new HaloPadder object  with example: obj = HaloPadder(halo_ex)